1.  Field of the Invention
The present invention relates to systems and methods for applying liquids to vegetation and, more particularly, to such systems and methods employing liquids under pressure through a nozzle or emitter. 
2.  Background of the Invention and Related Art
Irrigated crops are a critical component in securing global food production.  Globally, foods produced from irrigated crops comprise approximately 40% of world production.  Sustaining the level of irrigation needed requires large amounts of water withdrawn from rivers, lakes, reservoirs, and groundwater.  All together, crop irrigation makes up about 70% of global water withdrawals.  Wherever access to surface water is limited and productive aquifers are available, groundwater provides the main source of irrigation water.  In recent decades, the rate at which humans worldwide are pumping dry the vast underground stores of water that billions depend on has more than doubled—ScienceDaily (Sep. 23, 2010).  When groundwater abstraction exceeds the recharge rate over extensive areas for prolonged periods, non-renewable groundwater depletion will result leading to falling groundwater levels. 
Regional studies using the GRACE (Gravity Recovery And Climate Experiment) satellite observation revealed that considerable amounts of non-renewable groundwater resources are being abstracted in North East India, North West Pakistan, and California's Central Valley, most of which is used for irrigation—(Nature, Vol.  460, pp.  999-1002).  Further studies also reported depleting groundwater resources due to irrigation in the High Plains (Ogallala) aquifer, USA—(Geophysical Research Letters, Vol.  38, L03403).  Similarly, abstraction of groundwater resources at unsustainable levels is ongoing in areas of the Middle East, Africa, Australia, and China (Geophysical Research Letters, Vol.  37, L20402). 
Published research has widely reported beneficial effects on crop yield when irrigation water solutions are exposed to magnetic fields, resulting in more efficient use of available water resources (e.g., Irrigation with magnetized water enhances growth, chemical constituent and yield of chickpea (Cicer arietinum L.), Mahmoud Hozayn1* and Amira Mohamed Saeed Abdul Qados; Agronomy Dept.,  Agric.  and Biol.  Div.,  National Research Centre, El-Bohoth St., 12622 Dokki, Cairo, Egypt).  Spray equipment is used widely in irrigation systems to deliver water solutions to crops.  Research has demonstrated that better results are achieved when a magnetic field of sufficient strength is applied as close as possible to the spray nozzle and in direct contact with the liquid pathway, as taught in U.S. Pat.  No.  6,276,617 “Agricultural liquid application nozzle, system, and method” by the same inventor of the present invention and incorporated herein by reference in its entirety.  To achieve the full benefit of incorporating magnetic components into irrigation equipment, apparatus is needed for reconfiguring the wide range of spray equipment employed. 
Applicant is aware of the following U.S. Pat.  Nos.  concerning magnetic treatment of fluids, particularly water based solutions:
Vermeiren U.S. Pat.  No.  2,652,925 discloses a treatment device which produces a magnetic field and a passage for the liquid to be treated:
Menold U.S. Pat.  No.  4,265,754 discloses an apparatus for treating fresh water by producing a magnetic field in proximity to a flow of water within a water conduit. 
Zimmerman U.S. Pat.  No.  4,265,755 discloses a magnetic water treating device within a conduit.  This device provides easy assembly without adversely affecting the ultimate functional capability of the overall unit. 
Schiesser U.S. Pat.  No.  4,265,756 discloses a change device for sieves used for filtering plastic materials.  The sieves can be changed with this device without interrupting the transport of the material which is being processed. 
Kulish U.S. Pat.  No.  4,605,496 discloses a device for magnetic treatment of liquids by concentrating magnetic fields on the liquids to provide descaling and deliming. 
Weisenbarger U.S. Pat.  No.  4,711,271 discloses a magnetic fluid conditioner for abating the adherence of precipitates. 
Glass U.S. Pat.  No.  6,056,872 discloses a device for magnetic treatment of fluids using a plurality of magnets having different magnetic field strengths and arranged peripherally about a pipe or other fluid conduit within which is a flowing fluid. 
Barnes U.S. Pat.  No.  6,641,725 discloses apparatus for magnetic treatment of fluids by concentrating magnetic fields on the fluids using a flexible magnet. 
E. P. Klynev, Device for magnetic treatment of irrigation water, SU pat.#1217788 (USSR), Mar. 15, 1986 [C.A.:104(26)2302l9y]
Numerous studies conducted at university research centers globally have shown magnetic treatment of water based solutions applied to crops produces positive effects, particularly in terms of yield.  Applicant is aware of the following published works reporting study results and methods:
EFFECT OF MAGNETIZED WATER ON ESTERASE ISOZYMES IN THE LEAVES OF TOMTO PLANT; Jin Kunzhen; Wan Guanghui and Qiu Jianao (Department of Biology, Northwest University, Xi'an 710069)
RESEARCH ON THE EFFECT OF DIFFERENCE UPON GERMINATION AND GROWTH OF WHEAT WITH DIFFERENT RESISTANCE IN THE TREATMENT OF MAGNETIC FIELDS; Xi Gang; Yang Yunjing; Xue Song (Northwestern Agricultural University, Yangling Shaanxi, 7121002) (Shaanxi Academy of Agricultural Sciences, Yangling, Shaanxi, 712100)
BIOLOGICAL EFFECT ON THE GERMINATION AND GROWTH OF MUNG BEAN SEEDS UNDER LOW FREQUENCY MAGNETIC FIELD; ZHU Jian, LIU Xin, ZHONG Jikang, H U Zhenghai (1 School of Life Science and Technology, Tongji University, Shanghai 200092, China; 2 Science School, Tongji University, Shanghai, 200092, China; 3 Institute of Botany, Northwest University, Xian 710069, China)
EFFECT OF MAGNETIC FIELD ON WHEAT AND RICE CROWTH; Yi Yanli; Liu Xiaoyi; Wu Liyan Department of Soil Science, Shenyang Agricultural University
EFFECTS OF THE DIFFERENT MAGNETIC FIELD TREATMENTS ON THE PHYSIOLOGY CHARACTERISTIC OF SEVERAL PLANTS; FAN Ling-juan1, LI Yan-ru1, YANG Li-li2, ZHOU Xiao-mei1 (1.School of Life Science and Technology, Shanxi University, Taiyuan 030006, China; 2.Arid Farming Research Center, Shanxi Academy of Agricultural Science, Taiyuan 030031, China)
THE INITIAL STUDY ON THE INFLUENCE OF MAGNETIZED WATER TO VEGETABLE SEED GERMINATING; Gao Heping, Zou Liping, Xia Liaoyuan (Pepartment of Agronomy, Xiaogan University, Hubei 432000)
EFFECT OF EXTERNAL MAGNETIC FIELD ON PEROXIDASE SYNTHESIS AND ITS ACTIVATION DURING GERMINATION IN WHEAT; XI Gang; FU Zhi-Dong Northupestern Agricultural University, Yangling, Shaanixi 712100
EFFECTS OF ELECTRO-MAGNETIC FIELD ON THE PHYSIOLOGICAL CHARACTERISTICS OF CHLORELLA VULGARIS AND MECHANISMS ANALYSIS; WANG Hai-ying1, ZENG Xiao-bo2, GUO Si-yuan3 (1.  College of Chemistry and Life Science, South-Central University for Nationalities, Wuhan 430074, China; 2.  College of Pharmacy, Wuhan University, Wuhan 430072, China; 3.  College of Food & Biological Engineering, South China University of Technology, Guangzhou 510640, China)
THE EFFECT OF MAGNETIZED WATER ON SEED GERMINATION AND PHYSIOLOGIC NORM OF BALSAM PERA; XIAO Wang, WANG Yu-ling, GUAN Zhi-qiong Depantment of Biology, Guangdong Education Institute, Guangzhou 510310
EFFECTS OF SOIL MAGNETIZATION ON DEFENSIVE ENZYMES IN RAPE PLANTS; GU Jiguang, ZHOU Qixing (Key Laboratory of Terrestrial Ecological Process, Institute of Applid Ecology, Chinese Academy of Sciences, Shenyang 110016). 
EFFECTS OF SOIL MAGNETIZATION ON DROUGHT-RESISTIBILITY OF RAPE (BRASSICA CAMPESTRIS) AND THEIR MECHANISMS; GU Jiguang, ZHOU Qixing (Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016). 
MAGNETIC TREATMENT OF IRRIGATION WATER: ITS EFFECTS ON VEGETABLE CROP YIELD AND WATER PRODUCTIVITY; Basant L. Maheshwari, Harsharn Singh Grewal, School of Natural Science, CRC for Irrigation Futures, Building H3—Hawkesbury Campus, University of Western Sydney, Locked Bag 1797, Penrith South DC NSW 1797, Australia. 
EFFECTS OF MAGNETIZED WATER ON THE DISTRIBUTION PATTERN OF SOIL WATER WITH RESPECT TO TIME IN TRICKLE IRRIGATION; M. Khoshravesh, B. Mostafazadeh-Fard, S. F. Mousavi & A. R. Kiani, Water Engineering Department, College of Agriculture, Isfahan University of Technology, Isfahan 84156-83111, Iran, and Gorgan Agricultural and Natural Resources Research Center, Gorgan 41996-13475, Iran. 
PHYSIO-ANATOMICAL RESPONSES OF DROUGHT STRESSED TOMATO PLANTS TO MAGNETIC FIELD; Abdel-Fattah Hassan Selim, Mohamed Fathi EI-Nady; Department of Agricultural Botany, Faculty of Agriculture, Menufiya University, Egypt, Department of Agricultural Botany, Faculty of Agriculture, Kafrelsheikh University, Egypt. 
EFFECT OF TILLAGE METHODS AND USE MAGNETIC WATER ON GREENHOUSE CURCUMBER YIELD IN NORTH OF KHUZESTAN, IRAN; Elham Tayari and Amin Reza jamshidi; Department of Agricultural, Islamic Azad University, Shoushtar Branch, Shoushtar, Iran and Department of Agricultural Mechanization, Islamic Azad University, Shoushtar Branch, Shoushtar, Iran. 
Magnetizer Industrial Technologies, Inc. (Pipersville, Pa.) offers a clamp-on product called “Crop Booster” directed to magnetic treatment of water in irrigation systems.  Applicant is aware of the following published work reporting study results related to use of the “Crop Booster” product: MAGNETIC TREATMENT OF WATER AND ITS APPLICATION TO AGRICULTURE; Study by Dr. Israel J. Lin and Jacob Yotvat, Israel Institute of Technology Israel Institute of Technology.