초록
과수에서 생산량과 품질을 결정하는 조건 중 가장 중요한 것은 광이다. 차광은 광합성 효율을 떨어뜨리는 직접적인 원인으로 매실과 같이 생육기간이 짧은 과수에서 피해는 더 크게 나타난다. 본 연구에서는 최근 과수 주산단지에 일조방해에 의한 피해가 증가함에 따라 매실에서 차광조건이 생산량과 품질에 미치는 영향을 조사하였다. 차광시간이 증가함에 따라 매실의 평균 광합성 유효광선 (PAR) 조사량은 무처리 (304μmol/m2/s)에 비해 급격히 감소하여 8시간 차광에서는 142μmol/m2/s로 나타났다. 하루 중 광합성 효율이 최대(PAR 900~1,000μmol/m2/s)인 시간은 무처리와 차광 2시간은 5시간(오전 11시~오후 3시), 차광 4시간은 2시간(오후 1시~2시)이었으며, 6시간, 8시간 차광은 하루 종일 낮은 광량이 조사되었다. 차광시간에 따른 매실의 과중은 차광 2시간까지는 차이가 없었으나, 차광시간이 길어짐에 따라 유의하게 감소되었다. 산함량과 과형지수는 차광시간에 따라 유의한 차이가 없었으나 과실의 당도는 시간이 증가함에 따라 감소하였다. 결론적으로 매실의 2시간 이상의 차광은 과중과 당도를 떨어뜨리며 단위 면적당 생산량과 상품성 가치 하락에 직접적인 영향을 미친다.
Light is an important component among which plays a crucial role in determining the production and quality of fruit trees. Since the disturbance of light directly leads to reduced photosynthetic efficiency, their damage can be increased especially in fruit trees such as Japanese apricots with a short growing time. In this study, we investigated how the effects of shading condition can affect the production and quality of Japanese apricots according to increased damages by light disturbance in the main orchard complex. The average photosynthetically active radiation (PAR) level in Japanese apricots was rapidly dropped as the shading time was increased compared to the control (304 μmol/m2/s) and the PAR level decreased to 142 μmol/m2/s after shaded for eight hours. The maximum photosynthetic efficiency, with a PAR value of 900 to 1,000 μmol/m2/s, corresponds to the time period without shading and the time period with 2 hours of shading, and these times range from 11 a.m. to 3 p.m. And the time period for shading for 4 hours was from 1:00 p.m. to 2:00 p.m., and under conditions of shading for 6 and 8 hours, the effect was a low amount of light. There was no difference in the weight of Japanese apricots during 2 hours shading time, however, it was significantly reduced as shading time were increased. The difference of the acid content and L/D ratio was not significant on shading time, but the SSC was decreased as times going on. In conclusion, our results indicate that the shading for more than 2 hours make negative effects to decrease the weight and SSC and the yield and affects directly to drop in fruit quality.