Abstract
The objective of this study was to investigate growth and fruiting characteristics (e.g., nut qualities) of chestnut (Castanea cerenata) after applying various fertilizer treatments at the cultivation site in Suncheon. Fertilizer treatments were designed as follow: liquid fertilizer, chemical fertilizer, organic fertilizer, and control. Both liquid and chemical fertilizer treatments provided the best growth in height and basal diameter. In addition, these two treatments were very effective for crown width of the trees between both east-west and north-south orientation. The liquid fertilizer treatment was effective on total length of the fruiting branch and length of the bearing to terminate part. Both liquid and chemical fertilizer treatments produced the longest length of basal to bearing part compared to the other two treatments. The liquid fertilizer treatment showed the most thickened basal diameter of the fruiting branch and the greatest diameter of above and below the bearing burr part. Elongation Index of the fruiting branch (EI) was the highest with liquid fertilizer treatment and the remaining four indices (Production Index of fruiting branch, PI; Ratio of Diameter between below and above bearing burr part, RD; Growth Index of fruiting branch diameter, GI; Thickness Index of fruiting branch or dormant branch, TI) were the highest with the chemical fertilizer treatment. Total number of produced branch per fruiting mother branch and number of small and weak branches per fruiting mother branch were highest on the control and liquid fertilizer treatment; however, all treatments produced similar numbers. The chemical and organic fertilizer treatments produced a high number of fruiting branches per fruiting mother branch, while organic and liquid fertilizer treatments produced a high number of burr per fruiting branch. The rate of commercializing on the basis of nut weight and quantity was higher on control (87.5%) than chemical fertilizer treatment (84.6%); however, the rate was even lower on liquid fertilizer treatment (84.3%) and organic fertilizer treatment (82.7%). The liquid fertilizer treatment showed the highest average of nut weight, while chemical fertilizer treatment showed the highest average number of fruiting burr. There was no significant difference in average number of normal nuts per burr among treatments. The yield per tree was high on chemical (8.2 kg) and liquid (8.0 kg) fertilizer treatments, but there was no significant difference among treatments. In the rate of nut grade on the basis of nut weight and quantity, the liquid fertilizer treatment, 43.5% and 34.3% more than large nut respectively, produced higher value chestnuts compared to other treatments.
밤나무의 수고와 근원경은 액비처리구와 화학비료처리구에서 가장 많은 생장량을 나타냈으며 수관폭 생장량은 동-서방향과 남-북방향에서 각각 액비처리구와 화학비료처리구에서 우수하였다. 결과지의 총 길이와 착구부~정단부의 길이생장은 액비처리구에서 가장 우수하였으며 기부~착구부의 길이는 액비처리구와 화학비료처리구에서 동일하게 가장 길게 생장하였다. 결과지의 기부직경과 착구부의 상하부직경은 모두 액비처리구에서 가장 두껍게 생장하였다. 본 연구의 5개의 생장지수(결과지발생지수, 길이생장지수, 착구부상하직경비율, 직경생장지수, 굵기지수)에서 길이생장지수만이 액비처리구에서 가장 높고 나머지 모든 지수는 화학비료처리구에서 가장 높았다. 결과모지당 가지발생수와 소약지 개수는 무처리구와 액비처리구에서 많았으며 처리간 유사한 경향을 보였다. 결과모지당 결과지수는 화학비료처리구와 유기질비료처리구에서 많았으며, 결과지당 착구수는 유기질비료처리구와 액비처리구에서 많았다. 과실의 중량과 수량을 기준으로 한 상품화 비율은 무처리구(87.5%)와 화학비료처리구(84.6%)에서 높았으나 액비처리구의 상품화 비율은 각각 84.3%와 82.7%로 평균 수준이었다. 평균입중과 총착구수는 각각 액비처리구와 화학비료처리구로 가장 우수하였다. 함과수는 처리 간 차이는 없었으며 본당수확량은 화학비료처리구(8.2 kg)와 액비처리구(8.0 kg)에서 다수확성을 보였으나 처리간 통계적으로 유의한 차이는 없었다. 과실의 중량과 수량을 기준으로 등급을 구분한 결과, 액비처리구에서 대립 이상의 비율이 각각 43.5%와 34.3%로 가장 높아 액비처리에서 고부가가치의 고품질 밤이 가장 많이 생산되었다.
