為了解使用生長調節劑於控制落花生營養生長與生殖生長之可能性，本試驗乃以本省現行栽培種落花生小粒型(Spanish type)臺南選九號(TP-9)及大粒型(Virginia type)NCACC550為材料，於flowering –pegging stage開始，每週分二次噴施ABA,GA3, cytokinin及IAA 100mg/L，迄成熟期為止，結果如下：1. 落花生葉片葉綠素及可溶性蛋白質含量對各種生長調節劑具有不同株型間之反應。Spanish type在各種調節劑處理下，單位葉面積之chlorophyll均普遍下降，而Virginia type則反增。在兩型落花生植株中，GA3處理均較ABA, cytokin及IAA易降低單位葉面積之chloro-phyll含量。此外，除IAA施用於Spanish type及Virginia type增加Soluble protein外，其餘處理均無明顯變化。2. Spanish type植株在GA3處理下，減少葉柄數20%(相當於葉數)及葉重25%，而不受其他生長調節劑之影響。至於Virginia type在GA3處理下則減少葉柄數達40%，葉重達50%，此外，IAA處理亦有相似變化。3. Spanish type植株在GA3處理下，促使主莖長度增加28%，第一分枝長度增加11%，而總分枝數減少達25%；ABA則減少主莖長度28%及第一分枝長度15%，其他變化幅度較小。至於Virginia type則反應更加明顯，在GA3處理下，促使主莖長度增加82%，第一分枝長度增加65%，以及減少總分枝數15%，但ABA處理則無顯著變化。4. Spanish type植株在四種生長調節處理下，均減少子房柄數，但不影響單株莢果產量及子粒單粒重，而Virginia type在ABA,GA3及IAA三種生長調節劑處理下，因嚴重減少子房柄數23-63%，故子粒單粒重雖為明顯改變，仍造成夾數減少以致莢果產量顯著降低達28-38%。

In order to explore the possibility of applying plant growth regulators to alter comptition relationship between vegetative and reproductive growth of peanut (Arachis hypogaea L.) plants, four plant regulators including abscisic acid(ABA),gibberellic acid (GAs),cytokinin and indoleacetic acid (IAA) were applie respectively twice a week from middle flowering-pegging stage to maturity stage. Two cultivars,TP-9(Spanish type) and NCACC550(Virginia type),responded differently to four plant growth regulators. Chlorophyll contents per leaf area of Spanish-type plant decreased under the treatments,but increased for Virginia-type. For both plant types, GA3 treatment decreased chlorophyll content per leaf area more than other regulators. Besides, it is also found that leaf souble protein was not affected by treatment except increment induced by IAA for Spanish type and ABA for Virginia type. Under the four plant growth regulators treatments, the significant changes in vegetative growth of Spanish type plant included 28% increment of main stem length, 11% increment of primary branch length, but 25% decrement of total branch number by GA3 treatment. Besides, 28% decrement of main stem length and 15% decrement of primary branch length were caused by ABA. Such alterations expressed larger for Virginia type, especially 82% and 65% increments of main stem length and primary branch length respectively induced by GA3. nor yb ABA. Although stem growth of peanut plants was promoted by GA3, both leaf petiole number (representative of leaflet number) and leaf dry weight were reduced 20% and 25% respectively for Spanish-type plants,as well as 40% and 50% more for Virginia-type plants respectively. Furtherly, in spite of decreases of peg number of Spanish-type plant cause by for plant grwth regulators, both pod yield per plant and dry weight per kernel were not altered. But the sever reduction (23~63%) of peg number of Virginia-type plants under the ABA ,GA3 .and IAA applications individually resulted in 28~38% reduction of pod yield.