衰老沙田柚果园低产劣质原因与增产提质改造效果
Causes of Low Yield and Inferior Quality in Senile Shatian Pomelo Orchard and the Effect of Improving Yield and Quality

针对衰老沙田柚低产劣质、经济效益差等问题，总结了低产劣质原因，制定了改造技术措施，取得了明显的增产提质效果。结果表明，土壤偏酸、缺锌与硼，授粉质量差、管理不到位是低产劣质的主要原因；通过改造，26~27年生树处理区产量2559.67 kg/666.7m²~3026.24 kg/666.7m²，CK区1848.64 kg/666.7m²~1914.88 kg/666.7m²，处理比CK区增产33.67%~63.70%；处理区的商品果率96.70%，CK区86.70%，处理比CK提高11.53%；果实TSS含量10.6%~12.80%，比CK区的9.5%~11.0%提高11.58%~16.36%；全糖含量分别为8.56%、9.19%和9.80%，比CK的8.46%、7.74%和9.15%分别提高1.1%、18.73%和7.1%；Vc含量分别为105.18 mg/100ml、92.60 mg/100ml和73.91 mg/100ml果汁，分别比CK的94.25 mg/100ml、85.16 mg/100ml和71.37 mg/100ml果汁提高11.6%、8.74%和3.56%。
This paper aims at the problems of low yield, poor quality and poor economic benefit in senile Shatian pomelo orchard. The reasons of low yield and inferior quality are summarized. The technical measures of reconstruction were formulated. Obvious effect of increasing production and improving quality was obtained. The results showed that soil acidification, lack of zinc and boron, poor pollination quality and poor management were the main reasons for low yield and inferior quality. In the 26~27 years old orchard, the CK area was 1848.64 kg/666.7m²~1914.88 kg/666.7m², and the yield in the treatment area was 2559.67 kg/666.7m²~3026.24 kg/666.7m², which was 33.67%~63.70% higher than that in the CK area. The commodity fruit rate of CK area was 86.70%, and that of treated area was 96.70%, which was 11.53% higher than that of CK. The TSS content of fruits in CK area was 9.5%~11.0%, and the TSS content of fruits in treatment area was 10.6%~12.80%, which was 11.58%~16.36% higher than that in CK area. The total sugar content of fruits in CK area was 8.46%, 7.74% and 9.15%, and the total sugar content of fruits in treatment area was 8.56%, 9.19% and 9.80%, which was 1.1%, 18.73% and 7.1% higher than that in CK, respectively. The content of VC in the fruits of CK was 94.25 mg/100ml, 85.16 mg/100ml and 71.37 mg/100ml juice, respectively. The content of Vc in the fruits of the treated area was 105.18 mg/100ml, 92.60 mg/100ml and 73.91 mg/100ml juice, which was 11.6%, 8.74% and 3.56% higher than that of CK, respectively.