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A desk study of heat pulse effects on a tomato crop - HH3712SPC

Description
Background to research proposal:

Research project HH1329SPC was funded by DEFRA to study environmental factors that affect short-term yield prediction of tomato crops. As part of HH1329SPC, data was collected from four glasshouse compartments at HRI-Wellesbourne in 2000 to study the effects of a heat pulse event on the short-term yield and size distribution of tomato fruit. Limitations on the size of the experiment meant that only a single heat pulse treatment with a temperature lift of 4.50C for 7 days was tested on just two occasions during a single growing season.

HORTLINK HL01LPC was established in 1997 to investigate the environmental factors that cause deleterious effects on summer tomato fruit quality. As part of HL01LPC, a series of experiments using a minimum of eight compartments at the M-Block facility at Efford in each year between 1998-2000 was used to investigate the effects of a range of different short heat pulse events on tomato fruit quality. The program of work tested different pulse length treatments, different pulse magnitude treatments and at least three cycles of pulse periods in each compartment in each year. The fruit quality data from the project has been fully modelled as part of project HL01LPC but the fruit yield data has been examined by standard analysis of variance methods only.

Summary of research proposal:

The results from HH1329SPC can be used to show the pattern of yields following a single heat pulse event of 4.50C for 7 days (see ref. 6) but cannot be used to model the effects of different pulse lengths or different pulse magnitudes. Also, the results of HH1329SPC have very limited replication and do not provide information on seasonal interaction effects.

HL01LPC used pulses of duration either 3 or 7 days and magnitudes ranging between 200C and 260C with either an 8 week period (years 1998 and 1999) or a 4 week period (year 2000) between successive pulse applications on the same crop. The results from HL01LPC can be used to model the effects of different pulse lengths (see Fig 1) and different pulse magnitudes (see Table 1) on the magnitude and distribution of fruit yields following a heat pulse event and can also be used to provide tests for seasonal interaction effects.

We propose to develop quantitative models to predict the short-term effects of heat pulses of duration between 3 and 7 days and magnitude between 200C to 260C on a summer tomato fruit crop. We will model the impact of a temperature pulse on yield patterns over either an eight-week fruit development period (1998 and 1999) or over a four-week fruit development period (2000) following each heat pulse event.

The existing fruit quality data analysis programs developed for HL01LPC will be extended and modified to provide detailed analysis of heat pulse effects on tomato crop yield patterns and fruit size grade-out. The study will develop statistical regression models that will:

i) Quantify the effects of heat pulse duration on the pattern and distribution of fruit yields and size grades
ii) Quantify the effects of heat pulse magnitude on the pattern and distribution of fruit yields and size grades
iii) Test for interactions between heat pulse duration, heat pulse magnitude and seasonal and weather effects over a full summer cropping period
iv) Test for heat pulse effects on yield due to effects at anthesis

These models will provide quantitative predictions of the effects of different pulse temperatures and different pulse magnitudes on tomato fruit yield and will be used to extend and generalise the yield prediction models currently under development for project HH1329SPC. The extra model information from this project will introduce pulse magnitude and pulse length into the predictive models developed for HH1329SPC and will substantially increase the power of those models. The additional data from HL01LPC will also provide testing and validation for the data collected for HH1329SPC.

In addition, the fruit quality prediction models developed for HL01LPC will provide parallel predictions of the effects of heat pulses on fruit quality. The fruit yield and fruit quality predictions, taken together, will provide a comprehensive model of the effects of a heat pulse event on the commercial value of a glasshouse tomato crop.

Policy relevance:

The project will provide improved short-term prediction of tomato fruit yields and will improve crop efficiency and minimise wastage. The project will help meet the key DEFRA policy objectives of promoting a sustainable food supply chain and developing diverse, modern and adaptable farming systems.

Outputs and intended use of the results:

The outputs from this work will have two direct applications:

i) First, the outputs will be used to extend and generalise project HH1329SPC on tomato modelling and prediction supervised by Dr Steve Adams at HRI-Wellesbourne. Project HH1329SPC is due for completion in September 2003 and the results from this study will extend and generalise the range of the models developed for HH1329SPC and will also provide checking and validation of the models developed for that project.

ii) Second, the combined outputs from this study and from HH1329SPC will provide a database of results with application to the development of intelligent software for control of glasshouse environments for tomato crops. We will seek to develop a LINK Consortium to apply these results to the development of intelligent software for control of glasshouse environments using commercial software applied to commercial glasshouse holdings.
Objective
i) To quantify the effects of heat pulse duration on the pattern and distribution of fruit yields and size grades

ii) To quantify the effects of heat pulse magnitude on the pattern and distribution of fruit yields and size grades

iii) To test for interactions between heat pulse duration, heat pulse magnitude and seasonal effects over a full summer cropping period

iv) To test for heat pulse effects on yield due to effects at anthesis

Project Documents
• Final Report : A desk study of heat pulse effects on a tomato crop   (688k)
Time-Scale and Cost
From: 2002

To: 2003

Cost: £29,806
Contractor / Funded Organisations
Horticulture Research International
Keywords
Farming              
Horticulture              
Organic Farming              
Protected Cropping              
Quality              
Tomatoes              
Fields of Study
Horticulture
Horticulture