Gajendra Giri

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

Effect of preceding grain legumes on growth and nitrogen uptake of dryland pearl millet

SummaryIn a dryland cropping systems study preceding crops either of groundnuts, cowpea or pigeon pea were found to increase the early seedling vigour, rate of plant growth and grain production of the subsequent pearl millet. No such benefit was noted from a previous crop of mung. Grown after groundnuts and cowpea the unfertilized pearl millet removed from the soil 39.9 and 32.5 kg N compared to 18.9 kg N per hectare following a pearl millet crop. At harvest the number of viable nodules was the highest in groundnuts and cowpea. Especially in groundnuts the number of viable nodules increased after flowering stage.

Influence of dates of sowing on Brassica species under semi-arid rainfed conditions of north-west India

Field experiments conducted during the winter seasons of 1982–3 and 1983–4 in semi-arid rainfed conditions of north-west India indicated that sowing of Brassica species at the right time can considerably increase productivity. Sowing in the middle of October with daily mean temperatures around 26 °C produced 1·5 t/ha against 0·9 t/ha obtained from the crops sown 1 month later with daily mean temperatures around 20 °C. Under such conditions Brassica juncea cv. Pusa Bold (medium in stature and duration and bold seeded) gave the highest (1·66 t/ha) yield. Eruca sativa could withstand sowing at still lower temperature (19 °C). Increasing temperatures in the second fortnight of February adversely affected the productivity of a late-sown crop by reducing the reproductive phase.

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.

Partitioning of photosynthates, N and P in mustard as influenced by nutrient management in fodder sorghum (Sorghum Bicolor L.) - mustard (brassica juneca L.) cropping sequence

Abstract A field experiment was carried out to find out the effect of N, P and biofertilizers (Azotobacter and phosphate solubilizing bacteria [PSB]) on partitioning of photosynthates, N and P and growth and yield attributes and yield of fodder sorghum-mustard cropping system in north west India. It was observed that yield of fodder sorghum on fresh as well as dry weight basis obtained due to recommended dose of fertilizers (RDF, 60 kg N + 12.9 kg P ha−1) and half RDF + biofertilizers was not only highest but also significantly higher than that of half RDF and control. However, N and P uptake by fodder sorghum was significantly higher when supplied with RDF. Results on the succeeding crop of mustard showed that stems had a maximum share in total dry matter accumulation regardless of nutrient management practices. Up to 90 days after sowing (DAS), the total phytomass accumulation of mustard was statistically equal under previously applied RDF and half RDF + biofertilizers treatments. At later stages, RDF produced significantly higher dry matter accumulation. Regarding directly applied nutrients, RDF (80 kg N + 17.2 kg P ha−1) produced the highest phytomass throughout the crop growth period of mustard. Mustard crop gave significantly higher seed yield due to residual and directly applied RDF as compared to that of other residual and directly applied nutrients, respectively barring half RDF + biofertilizers. Only 22.5 – 24.0% of phytosynthates transformed into sink, i.e. harvest index (HI). However, more than 80% of N was partitioned into grain (HIN). Available N had a negative effect on nitrogen use-efficiency (NUE). Agronomic efficiency and apparent recovery of N in mustard were highest due to directly applied half RDF + biofertilizers.