행복드림 옥천 농업기술센터

                                             과실에서 안정생산과 품질향상에 크게 영향을 미치는
                                             기상재해는 봄철 발아기 부터 개화기에 걸쳐 저온이나
                                             서리에 의해 발생하는 늦서리 피해이다.
                                             늦서리 피해정도는 품종의 유전적인 소질에 따라서
                                             차이가 있으나, 생육 단계에 따른 내동성(耐凍性)의
                                             차이가 더 크게 영향을 미친다.
                                             한 화총내에서도 중심화가 측화보다 발육이 빨라
                                             늦서리 피해를 더 받기 쉽다.
                                             또한 피해 한계온도 보다 높더라도 지속시간이 길거나,
                                             온도 변화가 클 경우에 피해가 심하다.

                                            □ 꽃피기 전후 늦서리 대비

                                                 - 기상예보를 항시 청취하고 과원에 최고·최저온도계 설치,
                                                     저온에 대비
                                                 - 사과, 배 개화기 늦서리, 저온피해 예상시 지하수를
                                                     스프링클러나 미세살수 장치로 살수하면 수체온도
                                                     보호로 피해 최소화 가능
                                                 - 방상선 설치 2℃이하로 온도가 떨어질 때부터 가동
                                                     또는 왕겨 등 태우기(10a당 40개소 이상, 사방 5m 간격)

    
                                                     ○ 방상 방법별 효과 비교
                                                    
                                                         <미세 살수처리에 의한 늦서리 피해 방지효과>
                                                처리                        조사화총수(개)                                 화기피해율(%)
                                                                                                                                                중심화            측화까지         계
                                                살수법                             612                                            0.8                        0.0                 0.8
                         후지        
                                                 대    조                             300                                            7.3                     0.0                    7.3

                                                살수법                             300                                            6.0                     2.3                     8.3                        
                         추광        
                                                대    조                                309                                             9.3                 20.6                    29.8

    
                                                * 기상 조건 : 최저기온 -3.4℃, 풍속 : 0.45㎧ (2002. 4. 4)
                                                * 피해 화총 조사 위치 : 지상 1.0～1.5m 부위, 개화 후 조사

                                                                 <송풍법과 연소법의 방상효과(후지)>
                                                                                                                                                                     화기피해율(%)
                                                 처리                    조사화총수(개)                     중심화                측화까지            계
                                             송풍법                                 563                                            5.2                         0.2                    5.5
                                             연소법                                 769                                            7.2                         3.8                 10.9
                                                대    조                                 276                                            9.8                     4.3                 14.1

                                    * 기상 조건(2002. 4. 4. 12:00～4. 5. 06:00) : 최저기온 -3.5℃, 풍속 0.45 ㎧
                                    * 피해화총 조사위치 : 지상 1.0～1.5m 부위, 개화 후 조사    

                                                         <과종별 언피해 온도(℃)>
                                                    
                                구분                     12~1월                             2월                                3월                                4월                                5월
                                                                                                                                                                                                 싹트고                        열    매
                         생육단계         ----------잠잘 때-----------
                                                                                                                                                                                                    꽃필때                     맺힐때

                                사과                 -25 ~ -30                -30 ~ -35                -15 ~ -20                 -1.7 ~ -2.5                    -1.1
                                    배                    -20 ~ -25                -25 ~ -30                -15 ~ -20                 -1.7 ~ -2.8                    -1.1
                             복숭아             -15 ~ -20                -20 ~ -25                -10 ~ -15                 -1.1 ~ -1.7                    -1.1
                                포도                 -20 ~ -25                -20 ~ -25                -15 ~ -20                            -0.6                             -1.1