Luis Ibarra-Jiménez

Colored plastic mulches affect soil temperature and tuber production of potato

Abstract The main crops on which plastic mulch is widely used in Mexico include tomato, bell pepper, eggplant, melons, watermelons, and strawberry; however, very little research has been performed on potato. One of the main benefits associated with plastic mulching is the modification of the microclimate around the plant. To obtain a positive microclimate modification studies are required to understand how plastic mulch affects growth and yield of a given species. Previous field research assessing the response to colored plastic mulching in potato shows no consistent results on yield, maybe because it has been performed under different geographical latitudes. Potato in Mexico is conventionally cultivated on bare soil combined with various irrigation systems. The objective of the present study was to examine the effect of colored plastic mulches on soil temperature, growth, yield and photosynthetic response of potato plants. The experiment was conducted in Northeast Mexico and the treatments included were: black plastic mulch (BPM); white-on-black plastic mulch (W/B), silver-on-black (SPM), aluminum-on-black plastic mulch (APM) and a control that consisted of bare soil cultivated plants. Treatments were arranged in a randomized complete block design with four replications. Results suggest that average daily mean soil temperature was linearly and negatively correlated with total yield and yield of first-quality tubers. Total yield and yield of first-quality tubers of plants mulched with W/B, SPM and APM was significantly higher (p≤0.05) than those of control plants. Leaf area and shoot dry weight were increased when soil temperatures were higher due to the effect of radiation transmission to the soil, however, this decrease was associated with a decrease in tuber production. The results of our study indicate that plants grown under BPM, which induced the highest soil temperature, showed marginal difference in yield compared with control plants, suggesting that colored plastic mulches have a positive effect on yield through decreased rise in soil temperature.

Photosynthesis, soil temperature and yield of cucumber as affected by colored plastic mulch

Abstract Each crop may require a different root-zone temperature to achieve the maximum growth rate and yield. The temperature of the upper soil profile is determined by the soil properties, climate conditions, and site location, and can be either too high or too low for the crop requirements. A proper selection of plastic mulch can be used to modify the root-zone temperature to improve crop growth and yield. Cucumber plants grown in the field were exposed to different soil temperatures in two growing seasons under colored plastic mulches. Field studies were conducted during two growing seasons. Eight colored plastic mulches were tested at each growing season against bare soil. The objective of this study was to determine the effect of plastic mulch on heat accumulation as soil degree-day (DDsoil), photosynthesis rate, and yield of cucumber crop. The experimental design was a randomized complete block with nine treatments (eight colors of plastic mulch plus bare soil as the control) and four replications. The colors of the plastic mulches were: white-on-black, blue, white, black, black embossed, silver-on-black, red, and brown. DDsoil and plant photosynthesis were positively correlated with total yield, suggesting that increases in cucumber yield are due in part to an increase in soil temperature and plant photosynthesis. In conclusion, plants grown under the different colored plastic mulches had similar yields, and most of those plants had higher yields than plants grown in bare soil. We suggest that plastic mulch is useful for farmers of cucumber crops but the specific color of plastic mulch must be determined in each specific region.

Cultivation of potato – use of plastic mulch and row covers on soil temperature, growth, nutrient status, and yield

Potato is one of the most important crops in the world because of its high nutritional value; however, traditional cultivation in bare soil may render low yields and poor quality. Crop production efficiency can be increased by using plastic mulching and row covers to modify root zone temperature and plant growth, in addition to reduction in pest damage and enhance production in cultivated plants. However, there is little information demonstrating the effect of row covers in combination with plastic mulch on potato. The aim of this study was to assess the change in root zone temperature and its effect on growth, leaf nutrient, and yield of potato using plastic mulch of different colors, in combination with row covers. Seed of cultivar Mondial was planted in May 2012. The study included four plastic films: black, white/black, silver/black, aluminum/black, and a control with bare soil, which were evaluated alone and in combination with row covers removed at 30 days after sowing in a split-plot design. Higher yields were obtained when no row cover (43.2 t ha−1) and the white/black film (42.2 t ha−1) were used. Leaf nitrogen, sulfur, and manganese concentration were higher in plants when row cover was used; in contrast, no–row cover plants were higher in Fe and Zn. Mulched plants were higher in Mn concentration than control plants. There was a quadratic relationship between mean soil temperature and total yield (R2 = 0.94), and between plant biomass and total yield (R2 = 0.98), between leaf area with total yield (R2 = 0.98).

The effect of plastic mulch and row covers on the growth and physiology of cucumber

To determine the effectiveness of black plastic mulch alone and in combination with row covers, on growth and physiological changes of cucumber plants, 6 treatments were established in a randomised complete block design with 4 replications: bare soil (control); black polyethylene mulch alone (B); B plus a clear cover of perforated polyethylene (BRCP); B plus a white cover of perforated polyethylene (BRWP); B plus an Agribon cover of polypropylene (BRA); and B plus a Kimberly farm row cover (BRK). For the plants grown with mulch or mulch combined with row covers, the dry weight of leaves 50 days after seeding (DAS), and the dry weight of whole plants (at 50 and 110 DAS) were significantly (P<0.05) different from the control. Early yields of treatments B, BRCP, BRWP, BRA and BRK were 2.1, 1.9, 2.6, 1.9 and 2.4 times higher than the control, which yielded 10 t/ha. Total yields were increased by 9.7, 15.4, 19.8, 14.9 and 20 t/ha, over the control which yielded 104 t/ha. Increases in plant dry weight explained the changes in yield. Stomatal conductance may explain in part, the increase in photosynthetic rate, but may not explain yield increase.

Influence of double cropping on growth and yield of dry beans with colored plastic mulches

Existen numerosos estudios sobre el uso de cubierta plastica en la produccion de hortalizas, sin embargo esta muy poco documentado el cultivo simple o doble de frijol (Phaseolus vulgaris L.). El objetivo de este estudio fue cultivar frijol en dos estaciones de crecimiento consecutivas usando la misma cubierta plastica de diferentes colores y examinar la influencia de la temperatura del suelo en el crecimiento y rendimiento de frijol. El estudio fue conducido en Saltillo, Coahuila, Mexico, en la primavera y verano de 2008. Se usaron cuatro colores de acolchado plastico: blanco-sobre-negro, negro, plata-sobre-negro, aluminio-sobre-negro, y control de suelo desnudo. El diseno experimental fue bloques completos al azar con cuatro repeticiones. El porcentaje de radiacion fotosinteticamente activa (PAR) reflejada por las cubiertas tendio a ser mayor en el plastico blanco-sobre-negro y menor en cubierta negra. La temperatura media bajo la cubierta decrecio con el incremento en el porcentaje de PAR reflejada. La temperatura media del suelo se relaciono con rendimiento en 98% y 99% en la primera y segunda estacion de crecimiento, respectivamente. La relacion entre PAR y rendimiento fue 98% y 86% en la primera y segunda estacion de crecimiento, respectivamente. El efecto de la cubierta de color sobre el rendimiento fue significativo (p < 0,05) en la primera estacion de crecimiento, pero no en el segundo cultivo donde los tratamientos de cubierta y el control tuvieron un rendimiento similar, indicando que no siempre la cubierta aumenta el rendimiento.

Effect of plastic mulch and row covers on photosynthesis and yield of watermelon

The effect of row covers on watermelon (Citrullus vulgaris) grown on plastic mulch is well documented. However, row covers have not been adequately evaluated under Mexican growing conditions. Watermelon plants were grown on plastic mulch alone or with row covers to study their effect on photosynthesis, and early and total yields. Treatments were clear plastic mulch (C); black plastic mulch (B); B plus a Vispore cover of polypropylene (BV); B plus a white cover of perforated polyethylene (BW); B plus a clear cover of perforated polyethylene (BC); B plus an Agribon cover of polypropylene (BA); and bare soil as the control. For plants grown in treatment C, B or B combined with row covers, plant dry weight and number of leaves 40 days after seeding (DAS) were higher than the control (P<0.05), except BC which was comparable to the control. Total yields of treatments C, B, BV, BW and BA differed (P<0.05) from BC and the control. Total yields increased by 46.1, 43.2, 35.7, 41.6, 13.3, 15.4 and 35.8 t/ha for the C, B, BV, BW, BC and BA treatments, respectively, over the control, which yielded 27.1 t/ha. Total yield was highest for the C and the B treatment suggesting that there was no need for additional covers. The number of leaves per plant or dry weight per plant better explains the changes in yield than net photosynthesis rate. Stomatal conductance was explained in part by changes in photosynthesis.

Effect of colored plastic mulch on growth, yield and nutrient status in cucumber under shade house and open field conditions

ABSTRACT The aim of this study was to realize whether soil mulching, with different plastic mulch colors, is a suitable practice under shade house (SH) conditions for the culture of cucumber. To do so, cucumber was cultured mulched or not with black, blue, red or white-on-black plastic films under SH, and contrasted against mulched cucumber in open field (OF). Red mulch produced the highest shoot dry weight per plant and bare soil the lowest. However, it was the white mulch which produced the highest commercial yield per plant. Contrastingly, bare soil plants produced the lowest commercial yield. SH plants two folded photosynthetic rates compared to OF plants. Mulch color mainly impacted leaf phosphorus (P) and magnesium (Mg) content while the SH affected nitrogen (K), calcium (Ca) and magnesium (Mg). Our results confirm that soil mulching, and shading positively impact the cucumber yield and quality but also show that soil mulching under SH enhances cucumber crop.

Critical Evaluation of Different Techniques for Determining Soil Water Content

To efficiently operate any type of irrigation system, it is necessary to know when to irrigate and the quantity of water to apply during irrigation. To achieve this, it is very important to know the previously available soil water content. A good on-farm irrigation water management requires a routine monitoring of soil water moisture. Soil water must be maintained between a lower and upper limit of availability for an optimum plant growth. Soil moisture is a very dynamic variable that depends on plants evapotranspiration, irrigation frequency, drainage and rainfall. Measuring soil water content for determining the water depth allows avoiding the economic losses due to the effect of underirrigation on crop yield and crop quality, and the environmentally costly effects of overirrigation on wasted water and energy, leaching of nutrients or agricultural chemicals into groundwater supplies.

Soil solarization enhances growth and yield in dry beans

Abstract Dry beans are one of the most important crops in Mexico. However, in the last decade this crop averaged yields as low as 0.7 tons per hectare. Therefore, the purpose of this study was to test if soil solarization is a suitable pre-planting soil treatment to improve growth, nutrition and yield of beans in northeast Mexico. Five different periods of soil solarization were evaluated during the spring of 2008: 0, 30, 40, 50 and 60 days of soil solarization. Soil temperatures were recorded during soil solarization to estimate total heat units. After soil solarization bean seeds were sown in plastic-mulched rows and leaf area, potassium, calcium and magnesium concentration and yield were measured. Leaf area and concentrations of potassium, calcium and magnesium were increased by all treatments of soil solarization when compared with the non-solarized soil. Sixty days of soil solarization produced yields of 3.7 tons per hectare while no solarization produced yields of 2.1 tons per hectare. Soil heat units were positively correlated with yield, suggesting that the increase in yield is due to an increase in heat accumulation during soil solarization in addition to an increase of leaf area and to an enhancement of plant nutrition.

Macronutrient and micronutrient foliar sprays vs. water stage fruit split in pecan Carya illinoinensis

espanolEn el estado de Coahuila, Mexico, se reportaron perdidas economicas por rajado del fruto (RF) en nogal pecanero, probablemente relacionadas con carencias nutrimentales. Considerando lo anterior se evaluo la ocurrencia del RF en respuesta a fertilizaciones foliares en cultivares Wichita y Western. Para ello, se aplicaron macronutrimentos, micronutrimentos y una mezcla de ambos. A mediados del ciclo se estimo la ocurrencia de RF y se muestrearon hojas de apices que soportaban nueces no rajadas o rajadas para determinar su contenido nutrimental. El RF solo se observo en el cv. Wichita y aunque las aspersiones mejoraron su nutricion, no hubo diferencias estadisticas en el porcentaje de nueces rajadas comparadas con un testigo. Finalmente, los foliolos de apices con nueces rajadas presentaron mayor concentracion de nitrogeno (N) y menor concentracion de fierro (Fe) que aquellos con nueces no rajadas. Esto sugiere que el N y el Fe tienen una funcion importante en las causas del RF del pecanero. EnglishNorthern Mexican pecan growers from Coahuila reported yield losses caused by the water stage fruit split (WS) probably linked to nutrient deficiencies. Therefore, the effect of foliar fertilizations on the occurrence of WS in Wichita and Western pecan cvs. was evaluated. First, trees were sprayed with macronutrients, micronutrients or both. At the midpoint of the growing season, the percentage of split nuts was measured and the leaflets from leaves next to nut clusters containing non-split and split fruits were sampled to measure their nutrient concentration. The WS was only detected in Wichita trees, but even if the fertilizations improved their nutrient status, compared to non-fertilized control, they did not significantly impact the WS occurrence. However, leaflets next to split fruit containing clusters showed higher nitrogen (N) and lower iron (Fe) concentration than leaflets next to non-split clusters. This suggests that N and Fe play an important role on the WS disorder.