32 REPORT OF THE AGRICULTURAL RESEARCH INSTITUTE 



of Agriculture in India. A number of types have been 

 isolated which are being tested for yield under various 

 conditions. A few of these have been distributed for pre- 

 liminary trials outside Pusa. 



As pointed out in the last annual report, the yield of 

 gram like that of indigo depends on the aeration of the 

 roots and nodules. If, however, this crop is grown on well 

 ventilated soils which are also rich in combined nitrogen, 

 the yield of seed always falls off although the amount of 

 growth is enormous. When the crop obtains a large 

 amount of nitrate in solution from the soil and also forms 

 nodules, it is overstimulated and readily becomes too rank. 

 The heaviest and best-ripened gram is always grown at Pusa 

 on well-aerated plots which are distinctly poor in available 

 nitrogen. In the. past season, the best crop of gram was 

 obtained by late sowing on a thikra plot immediately after 

 the removal of a heavy crop of patwa (Hibiscus cannabi- 

 nus). Java indigo grown for seed sometimes behaves in a 

 very similar manner and experiments on this point are now 

 in progress. 



Oil-seeds. 



The work so far done on safflower (Carthamus tinc- 

 torius, L.) and rai (Brassica juncea, H. F. and T.) has just 

 been published in the Botanical Memoirs. 



The study of Indian linseed has been begun and an 

 attempt is being made to produce a large seeded linseed for 

 the plains. At present, the types grown on the alluvium 

 have very small seed, the large seeded forms being produced 

 on the soils of Central India. These two classes of varie- 

 ties are otherwise quite different — those from Central India 

 with large seeds having a deep root system to suit the black 

 soils while those of the plains are surface rooted. Crosses 

 are being made between these types with the object of pro- 

 ducing for the alluvium new surface-rooted kinds with 

 large bold seeds. In addition to the inheritance of size of 

 seeds, this study ought to provide interesting results on the 

 genetics of root- development. 



