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.

S U M M A R YBrassica carinata (an uncultivated species) was compared with other oilseed species already under cultivation in India, on irrigated and rainfed soils. B. carinata yielded very well in a wide range of environments partly because it had a large number of primary and secondary racemes. It also showed better environmental adaptation and substantial resistance to pests and disease.Rapeseed and mustard are together the second largest oilseed crop in India. The rapeseed group includes three cultivars of Brassica campestris, namely toria, yellow sarson and brown sarson. B. campestris is a winter season (October to March) oil crop of irrigated and rainfed soils with well conserved moisture. B. tournifortii and Eruca sativa are the other oilseed crops generally grown in dryland areas with a high moisture deficit. B. juncea, commonly called mustard, is another important species widely cultivated in India, Pakistan, Bangladesh and China for its edible oil. B. napus, an amphidiploid of B. campestris and B. oleracea, is occasionally grown in northern and north-west regions of the country because of its resistance to some insects and diseases, major constraints on yield. B.carinata is an oil yielding species not yet in commercial cultivation. The present study was planned to test the potential of this species as a new oil crop in India. MATERIALS AND METHODSTwo experiments were carried out at the Indian Agricultural Research Institute, New Delhi. Experiment 1 (irrigated)This experiment was sown on irrigated sandy-loam soil on 7 October 1980 using 57 cultivars of B. campestris and one each of B. napus, B. carinata, B. juncea and Eruca sativa. All the three varietal forms of B. campestris (brown sarson, yellow sarson and toria) were included. A randomized block design (RBD) was used with three replications and 1.8 X 3 m plots. The crop was sown on ridges spaced 60 cm apart and thinned to 10 cm between plants at

SummaryField 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.

SUMMARYField experiments made for 4 years between 1976–7 and 1979–80 in a semi-arid environment of north-west India showed that the productivity of dryland unirrigated wheat can be increased considerably by adjusting the date of sowing to conducive atmospheric temperatures. Sowing in the middle of November when daily mean temperatures ranged between 19 and 21 °C produced yields ranging between 2·6and 3·5t/ha (averaged over the 4 years) compared with 1·4–3·3 t/ha obtained from the crop sown by mid-October when the daily mean temperature ranged between 24 and 26 °C. The tall cultivar C 306, a derivative of winter x spring wheat cross, could withstand sowing at higher temperatures (mid-October) more than the spring wheats. High temperatures prevailing during the seedling stage of spring wheats shortened their vegetative growth and initiated early differentiation. Night temperatures above 13 °C coupled with day temperatures of 33–35 °C in the last fortnight of October adversely affected the tillering of spring wheats sown on 15 October and produced smaller spikes with few fertile spikelets.

SUMMARYA field trial was made for 3 years at the Indian Agricultural Research Institute, New Delhi under semi-arid rainfed conditions to study the effect of the preceding season cultural practices on mustard and to assess the possibility of double cropping, and the results are discussed. Preceding season cultural practices, i. e. ploughing in fallow or growing cow pea for fodder or mung for grain (both short-duration crops) increased the yield of the mustard crop compared with no tillage or growing pearl millet in preceding season. Yield of mustard following tillage, fodder cow pea or mung with mulch was similar; hence it is concluded that double cropping is possible under such conditions instead of conventional tillage-mustard, monoeropping practice. It is also concluded that frequent ploughings could be greatly reduced to give few but more effective cultivations, but more research into reducing cultivation during the preceding season should be carried out.