英语翻译The response of two peanut cultivars (Tainan 9 and SK 38

英语翻译The response of two peanut cultivars (Tainan 9 and SK 38) to applications of six boron (B) rates (H3BO 3 at 0,0.12,0.25,0.5,1 and 2kg B ha -1) at two calcium levels [nil (-Ca) or CaSO 4 at 100kg Ca ha-~(+Ca)] to a B-deficient Oxic Paleustult was studied in a pot experiment.Without added Ca,both cultivars had low seed yields and gave only small responses to B.Similarly,without added B,both cultivars had low seed yields and did not respond to Ca.But,with added Ca or B,they responded strongly to B and Ca,respectively.In both cultivars,deficiencies of Ca or B depressed seed dry weight by depressing seed size by over 75%.Boron deficiency further depressed seed dry weight by decreasing the number of seeds per plant by decreasing the number of seeds per pod in Tainan 9,and the number of pods per plant in SK 38.Seed dry weight was depressed more than pod dry weight,so that both Ca and B deficiencies severely depressed the shelling %.With added Ca,Tainan 9 responded to lower levels of B than SK 38,reaching maximum seed dry weight at 0.12 kg B ha- 1.At this low level of B,SK 38 yielded only half the seed dry weight of Tainan 9.But SK 38 continued to respond to increasing levels of B to 2 kg ha -1,producing a maximum seed yield 40% higher than Tainan 9.The results indicate that where all other nutrients are adequate,SK 38 will yield better than Tainan 9 on soils with high B,but worse on soils with low B.The implications of these findings for the selection of peanut cultivars are discussed.Peanut is widely grown in tropical and sub- tropical regions,often on sandy soils with low levels of Ca or B (Cox et al.,1982).In the northeast region of Thailand,where it is grown on sandy soils by farmers who use very little fertilizer,empty pods or pods with shrivelled seed are common problems in peanut (OAE,1987).The problems appear to be more severe in varieties with three seeds per pod than those with two seeds per pod (Toomsan,personal com- munication).Pod filling in peanut is known to be strongly depressed by inadequate Ca in the soil (Cox et al.,1982).On such soils,application of Ca generally increases seed yield,but in Thai- land treatment of peanut with Ca has given inconsistent results (FAO,1973).In the work reported by the FAO,no micronutrient fertiliz- ers were included with the basal nutrients.Sub- sequent studies have shown B deficiency is rela- tively widespread in Thailand (Keerati-Kasikorn et al.,1987; 1988; Netsangtip et al.,1987; Rerkasem et al.,1988),and application of B fertilizers to peanut crops increased seed yield,quality and size (Keerati-Kasikorn et al.,1987; 1988; Rerkasem et al.,1988).