R. De

Intercropping maize and sorghum with soya beans

Field trials were made in the rainy seasons of 1970–4 at the Indian Agricultural Research Institute, New Delhi, to evaluate several systems of intercropping maize and sorghum with soya beans. Maize yields were not affected by intercropping with soya beans but sorghum yields were reduced. Though the yield of soya beans when intercropped was less than that of a sole crop, the combined grain yield of the two crops in an intercrop was more than the individual components. Land equivalent ratio (LER) increased to a maximum of about 48 and 31% by intercropping maize and sorghum with soya beans compared with the cereal sole crops. Maize rows planted 120 cm apart and intercropped with two rows of soya beans or sorghum planted 90 cm apart intercropped with one row of soya beans proved to be the best intercropping pattern.

Modification of water balance of dryland wheat through the use of chlormequat chloride

In field trials made for two years in the dry period of a semi-arid tract under natural precipitation at the Indian Agricultural Research Institute, New Delhi, overnight seed-soaking of wheat in 0·5% solution of 2-chloro-ethyl-trimethyl ammonium chloride (CCC) prior to sowing increased the grain yield. When treated with foliar application of the chemical in concentrations ranging between 40 and 1000 mg/1, wheat plots yielded better than did the untreated control, but no consistency was noted between the concentrations or stages of their application. The benefit from CCC was due to more root growth, increased stomatal resistance and higher leaf water potential. Treated plants extracted more water from deeper soil layers, increasing their water-use efficiency.

Effect of Preceding Grain Legumes on Dryland Pearl Millet in NW India

Experiments carried out in northwest India show that yields of pearl millet were significantly increased when grown after legume crops such as groundnut (22.6%), cowpea (24.2%) or pigeonpea (12.2%) instead of after pearl millet. A previous crop of short-duration mung did not affect the yield of pearl millet. Benefits from previous crops of groundnut and cowpea were equivalent to about 60 kg N/ha applied to a pearl millet crop following a previous crop of pearl millet

Grain and fodder legumes as preceding crops affecting the yield and N economy of rice

Des experiences realisees sur 2 ans montrent que des precedents culturaux comme amberiques, doliques, haricots, haricots mungo, accroissent le rendement en grain et en paille du riz en culture suivante en relation avec des antecedents culturaux de mais fourrager ou de guar

Studies on the effect of nitrogen fertilizer, row spacing and use of antitranspirants on rapeseed ( Brassica campestris ) grown under dryland conditions

An experiment is desoribed which was conducted for 2 years under dryland conditions of north-west India to evaluate the optimum rate of application of N fertilizer and plant population density for a rapeseed crop. Stomata closing (phenyl mercuric acetate), film forming(Mobileaf) and reflective type (kaolinite) antitranspirants were used to examine their effectson conservation of stored moisture for a possible increased water use efficiency under drylandconditions. The rapeseed crop responded to N fertilizer and it was profitable to use 53 kg N/ha xinder these conditions. In a drier year a wider row spacing of 60 cm (1·1 x 106 plants/ ha) was significantly better than narrower spacing of 30 cm (2·2 xlO5 plants/ha). Plants grown in wider row spacings utilized less water during the vegetative and flowering stages than those grown in closer spacings. The relative water content of leaves sprayed with antitranspirants was greater than in the control plants. The leaf temperature of the kaolinite-treated canopy was 1·5 °C lower than the ambient air temperature. Averaged over 2 years, the film-forming antitranspirant Mobileaf increased the seed yield by 26% while spraying with phenyl mercuric acetate at 50 and 75 days and kaolin application at 50 days increased the rapeseed yield by 11, 18 and 17% over the no antitranspirant treatment.

Modification of irrigation requirement of wheat through mulching and foliar application of transpiration suppressants

SummaryField experiments on wheat for 2 years showed a beneficial effect of organic mulch (rice straw), reflective transpiration suppressant (kaolin) or metabolic antitranspirant (alachlor) by decreasing the evapotranspiration (ET) losses of soil water, increasing grain yield and thus water use efficiency. Increase in grain yield was due to an increased tiller survival, longer spikes and more spikelet fertility. The number of shrivelled kernels per spike was reduced by ET control measures. A combination of mulching and transpiration suppression brought about a saving of 1 irrigation on a clay-loam soil and at least 2 irrigations on a loamy-sand soil. Without the ET control measures 4 irrigations were needed on a clay-loam soil and 6 on a loamy-sand soil for maximum productivity.

Effect of nitrogen rates, mulching and antitranspirants on water use and water use efficiency of barley ( Hordeum vulgare L.) varieties grown under dryland conditions

Field experiments were made under natural rainfall during the winter seasons of 1972–3 and 1973–4 at the Indian Agricultural Research Institute, New Delhi, to study the soil water use by barley varieties as influenced by nitrogen rates, mulching and foliar application of antitranspirants. Both Ratna and Vijaya varieties of barley had similar efficiency of water use. Total water use was not much different for various treatments but straw mulch and kaolin decreased evapotranspiration at tillering and pre-flowering stages enabling the plants to use more water at critical stages of grain formation. Application of nitrogen, straw mulch and a foliar coating of kaolin increased the efficiency of water use.

Time of application of farmyard manure and fertilizer nitrogen on the growth, yield and nutrient uptake of dryland wheat

Experiments made for 4 years in the seasonally dry period of the monsoon environment of north-west India showed that the application of farmyard manure (FYM) with the onset of monsoon rains (in early July) was more advantageous for the growth and yield of wheat than its application at the end of the monsoon season in mid-September. Fertilizer N drilled into the soil with the cessation of rains was better utilized by wheat than that applied at sowing in mid-November. A combination of the organic matter and urea was better than their application separately. N, P and K removal by the wheat crop was significantly increased by FYM and urea application. The time of their application influenced the nutrient removal by the crop in the same way as it affected its growth and yield.

Plant growth and seed yield of sorghum when intercropped with legumes

Field experiments made for 2 years under semi-arid unirrigated conditions of north India examined the physiological factors affecting the growth and yield of sorghum when intercropped with groundnut ( Arachis hypogaea ), mung ( Vigna radiata ) or cow pea ( V. unguiculata ). Dry-matter production and leaf area index of sorghum were increased when intercropped with any of the legumes. The mixture advantage was reflected in delaying the senescence of sorghum leaves. Maximum grain and stover yields of sorghum were obtained in a mixture with mung or cow pea. The higher seed yield resulted from more seeds per panicle and greater panicle and 1000-grain weight.

Effect of mulching and kaolin foliar spray on mung ( Vigna radiata ) – rapeseed ( Brassica campestris ) double cropping system under rainfed conditions

Results are described of an experiment made at the Indian Agricultural Research Institute, New Delhi, for 4 years under semi-arid seasonally dry tropical conditions to explore the possibilities of double cropping in the traditionally monocropped areas. Use of straw mulch did not increase mung yield in the monsoon season with welldistributed rainfall but increased its yield in a year when the monsoon receded early. Irrespective of rainfall pattern, mulching helped conserve enough moisture in the top 30 cm of soil to enable germination and quick establishment of the rapeseed crop. Mulching continued in the rapeseed crop conserved soil moisture until the flowering stage and increased the yield of rapeseed by 23%. Kaolin, a reflectant material applied at the preflowering stage, also increased seed yield of rapeseed.