Yield responses of some economically important crop plants due to
foliar applications of low
concentrations of 28-homobrassinolide (HBR) were studied in experiments
conducted at research
stations and in farmers' fields in India during 1989–95. Foliar
sprays of different concentrations of
HBR were applied at tillering and spike/panicle initiation in wheat
(0·5 and 1·0 mg/l) and rice (0·25,
0·50 and 1·00 mg/l); at flowering and pegging in groundnut
(0·25 and 0·50 mg/l); 30 and 45 days after
sowing (DAS) in mustard (0·25 and 0·50 mg/l); 25 and 35 days
after emergence in potato (0·25 and
0·50 mg/l); and 30, 50, 70 DAS in cotton (0·1 and 1·0
mg/l). The HBR treatments significantly (P<0·05 and
P<0·01) increased grain yields in wheat, rice and mustard,
pod yields in groundnut, tuber
yields in potato and seed cotton yields, over control. The extent of yield
improvement due to HBR
was influenced by crop species, concentration of HBR, plant growth stage at
application and frequency of application.