Cucurbit Genetics Cooperative Report 19:27-29 (article 10) 1996
Zhongli Ji, Huanwen Meng and Hongwen Cui
Northwestern Agricultural University, Yangling, Shaanxi, 712100, P.R. China
Introduction. The northern part of China is in the temperate growing zone. The cold monsoons of the Northwest are responsible for a longer cold season in China than in other countries of similar latitude. As a result, vegetable production is unfavorable during this season. However, microclimates can be established within greenhouses constructed of plastic, which allow for favorable vegetable production at this time of year. This important horticultural practice is used for the breeding and production of cucumber. The paper examines heat sources used in such greenhouses and their efficiency of operation.
Materials and Methods. Seven cucumber varieties (BG3, BG5, ED6, ED10, FC15, FC17, and ME18) from the breeding program at Northwestern Agricultural University, P.R. China, were evaluated. DH23 cucumber was used as a check variety in the field plot experiments described herein. Experiments were designed such that varieties were arranged in a randomized complete block design with 3 replications, and plant-two-rows in plastic greenhouses from February to June, 1995. Thirty plants were examined in each replication on 4.4m2 centers. Air temperature was sampled at a height of 1.5m at the center of the greenhouse and at a given point 1.5m height outside the greenhouse. The air temperature sampling times were 8L00, 14:00, and 20:00 HRS., Peking time. The variables (XN ) recorded were: X = {X1 ,X2, X3 }; where X = sum for all cucumber varieties examined, X1 = total fruit yield, X2 = cumulative temperature 10 C from February to June 1995 inside plastic greenhouse and X3 = disease resistance of the cucumber varieties (% of undamaged control). The matrix (A) of coefficients of the variables assessed was: A = [0.5, 0.3, 0.2]; where A = matrix of coefficients of the variables assessed; 0.5 – coefficient of X1, 0.3 = coefficient of X2 , and 0.2 coefficient of X3 . Fruit grades (YN ) of varieties were designated as: Y = [Y1, Y2 , Y3 }; Y = sum for all cucumber grades assessed, Y1 = grades of unimproved (acceptable) varieties examined, Y2 = grades of improved varieties examined and Y3 = grades of inferior varieties examined.
The operational equation used for X1 and X2 was:
| 1 | x 1,2> a1 | |
| u (X1 X2) = | X1-a2
a1-a2 |
a1 > x1,2 > a2 |
| 0 | a2 > x1,2 |
where u(x1 x2 ) = the functional value of the x1 and x2 , a1 = the lower limit of the fruit grades of acceptable varieties, and a2 = the upper limit of the fruit grades of inferior varieties. The operational equation used for disease resistance of the cucumber varieties was:
| u (x3 ) = | Xi – Xmin
Xmax – Xmin |
where u(X3 ) = the functional value of X3 , Xi = observation date, Xmax = the maximal value of the observation date and Xmin = minimal value of the observation date.
Results and Discussion. Air Temperature. The daily mean air temperature and the cumulative temperature of 10 C were higher inside than outside the plastic greenhouse. The monthly mean air temperature in March was 6.9 C higher inside the greenhouse than outside. The monthly mean air temperature in April was 5.5 C higher inside than outside the greenhouse. The cumulative temperature 10 C in March was 18.6 C higher inside the greenhouse than outside the greenhouse in April (Table 1).
Resistance to Cold Stress. A table of differential criterion was constructed from the observational data and experiences of horticultural experts (Table 2).
Grade Evaluation. Values obtained from equations 1 and 2 allowed for the computation of functional values for total yield of cucumber in each experiment, cumulative temperature 10C, disease resistance ratings, and the functional values of grade matrixes. The results are as follows:
Table 1. A comparison of air temperature and cumulative temperature of~lOC inside and
outside plastic greenhouse.
Month |
Mean air temperature |
Cumulative temperature of ≥10C |
||
Inside |
Outside |
Inside |
Outside |
|
| March | 14.6 | 7.7 | 426.6 | 0 |
| April | 19.1 | 13.6 | 574.3 | 408.0 |
| May 1-7 | 21.5 | 16.5 | 150.3 | 115.1 |
Table 2. Differential criterion used for classification of cucumber varieties.
Factors |
Acceptable varieties(Y1) |
Improved varieties(Y2) |
Inferior varieties(Y3) |
| Total output (X1 ) | >0.90 | 0.70-0.89 | ,0.70 |
| >10C (X2 )1 | >0.90 | 0.75-0.89 | <0.75 |
| Disease resistance | >0.95 | 0.80-0.94 | <0.80 |
1Cumulative temperature
Table 3. Matrixes used in the calculation of fruit grade evaluation of the cucumber varieties examined.
Fruit Grade Components |
Results of Evaluation |
||||
Code name of cucumber varieties |
Matrixes |
Y1 |
Y2 |
Y3 |
|
| BG3 | B3= | 0.6250 | 0.3750 | 0 | good seed |
| BG5 | B5= | 0.6240 | 0.4412 | 0.2941 | intermediate seed |
| ED6 | B6= | 0.3809 | 0.5714 | 0.477 | intermediate seed |
| ED10 | B10= | 0.2000 | 0.3000 | 0.5000 | bad seed |
| FC15 | B15= | 20.6250 | 0.3750 | 0 | good seed |
| FC17 | B17= | 0.2124 | 0.2567 | 0.5310 | bad seed |
| ME18 | B18= | 0.29140 | 0.4412 | 0.2647 | intermediate seed |
| DH23(CK) | B23= | 0.4414 | 0.2627 | 0.2941 | good seed |
| BG3 R3 = | Y1 | Y2 | Y3 | X1
X2 X3 |
| 1 | 0 | 0 | ||
| 0,6667 | 0.3333 | 0 | ||
| 1 | 0 | 0 |
| ED10 R10 = | y1 | y2 | y3 | X1
X2 X3 |
| 0 | 0 | 1 | ||
| 0 | 0.3333 | 0.6667 | ||
| 0.3333 | 0.6667 | 0 |
| BG R5 = | 0 | 0.6667 | 0.3333 | X1
X2 X3 |
| 0 | 0.3333 | 0.6667 | ||
| 1 | 0 | 0 |
| FC15 R.15 | 1 | 0 | 0 | X1
X2 X3 |
| 0.6667 | 0.3333 | 0 | ||
| 1 | 0 | 0 |
| ED6 R6 = | 0.3333 | 0.6667 | 0 | X1
X2 X3 |
| 0.3083 | 0.6500 | 0.0417 | ||
| 0.8333 | 0.1667 | 0 |
| FC17 R17 = | 0 | 0 | 1 | X1
X2 X3 |
| 0.1333 | 0.2417 | 0.06250 | ||
| 0.3333 | 0.6667 | 0 |
| ME18 R18 = | 0.3333 | 0.6667 | 0 | X1
X2 X3 |
| 0.2000 | 0.2500 | 0.2500 | ||
| 1 | 0 | 0 |
| DH23 R23 = | 0.6667 | 0 | 0.3333 | X1
X2 X3 |
| 0.3333 | 0.6667 | 0 | ||
| 1 | 0 | 0 |
Composite operations (B) for matrix A and matrix R are: B = AOR. Data resulted in the establishment of matrix B which is a comprehensive evaluation for the cucumber varieties. According to U-max, the data resulted in the definition of classes for the cucumber varieties examined (Table 3).
The cold winter monsoon in northern China produces lower winter temperatures than in other countries of identical latitude. For example, latitude is greater in Cologne, Germany (50 ˚ 56’N) than in Harbin, China (45 ˚ 45’N) but the mean monthly temperatures in December to February are 18.8 – 21.8 C more in Cologne than in Harbin, China. While the mean air temperature in January is -1.0C in Xi’an, China (34’15’N) and 3.7C in Tokyo, Japan (35 ˚ 41’N), the mean air temperature in February is 2.1 C in Xi’an and 4.3 C in Tokyo. Moreover, there are lower air temperatures in Xi’an than in Tokyo. The winter climate of China allows plastic greenhouses to accumulate solar energy which increase inside ambient temperatures. This microclimate is beneficial for vegetable growth.
Literature Cited
- Staub, J. 1995. Problems associated with map construction and the use of molecular markers in plant improvement In: Lester, G.E. and J.R. Dunlap, eds. Proceedings Cucurbitaceae ‘;94: Evaluation and enhancement of cucurbit germplasm. p. 86-91.